288 BLACKBIRDS, ORIOLES, ETC. 



sparrows, vireos, wrens, and w^arblers, the birds most frequently 

 imposed upon are so small that the cowbird's big, crowding nestling 

 will be the one to survive when it is a question of size and resisting 

 power." {Birds of Village and Field.) 



495a. M. a. obscurus {Gmel.). Dwarf Cowbird. 



Similar to M. afer, but smaller. Male : length (skins) 6.00-7.10, wing 

 3.78-4.10, tail 2.4o-2.87, bill .62-.70. Female : length (skins) 5.61-6.30, 

 wing 3.37-3.70, tail 2.27-2.62, bill .5.5-.62. 



Distribution. — Breeds from southern Texas to southwestern Arizona, 

 and south to Lower California and Mexico. 



Eggs. — Deposited in nests of other birds, similar to those of M. ater. 



GENUS CALLOTHRUS. 



496. Callothrus robustus( Ca6.). Red-eyed Cowbird. 



Bill shorter than head, stout, conical, distinctly ridged, upper outline 

 slightly curved ; neck Avith soft, dense, erectile ruff ; four outer primaries 

 with inner webs curiously sinuated and emarginated. Adult male : iris 

 bright red ; body and erectile ruff black, with soft bronzy luster ; wings 

 and tail glossed with bluish, greenish, and purplish. Adult female: dull 

 black, somewhat glossed with bluish green ; neck ruffs much smaller than 

 in male. Young male : sooty black, under parts with feathers edged with 

 paler. Young female : paler and grayer than young male. Male : length 

 (skins) 7.75-8.80, wing 4.40-4.73, tail 2.98-3.24, bill .88-.94. Female: 

 length (skins) 6.50-8.10, wing 3.84-4.16, tail 2.52-2.94, bill .78-.84. 



Distribution. — Breeds from southern Texas south through eastern Mex- 

 ico to Central America ; migrates to Panama. 



Eggs. — Deposited in nests of other birds, usually 4, pale bluish green, 

 unspotted. 



On the coast prairies of the Rio Grande Valley in Texas the red- 

 eyed cowbird may be seen on the roadside fences. His strikingly 

 red eyes and handsome glossy black coat mark him at a glance from 

 the other cow^birds, and when he raises his neck ruff he seems indeed 

 a distinguished personage. 



GENUS XANTHOCEPHALUS. 



497. Xanthocephalus xanthocephalus (Bonap.). Yellow- 



headed Blackbird. 



Bill decidedly shorter than head, its depth through base less than half 

 the length of the exposed culmen ; culmen straight, flattened ; sexes dif- 

 ferent in size ; wing long and pointed ; tarsus nearly one fourth as long 

 as Aving ; claws large, lateral ones reaching beyond base of middle one. 

 Adult male in summer : black except for yellow or orange of head, throat, 

 and chest, and white patch on wings. Adult male in winter : similar, but 

 yellow of top of head obscured by brownish tips to feathers. Adult 

 female : brownish, throat and chest dull yellowish, breast mixed with 

 white. Young male in first ivinter : similar to female, but larger and deeper 

 colored. Male : length (skins) 8.60-10.10, wing 5.32-5.73, tail 3.66-4.27, 

 bill .83-.99. Female : length (skins) 7.50-8.30, wing 4.33-4.64, tail 3.10- 

 3.45, bill .77-.83. 



Distribution. — Western North America from British Columbia and Hud- 



